The Effect of Fertilization and Turfgrass Species on the Rhizosphere Microbial Community Structure.

Professional turfgrass managers, as well as other consumers, have shown increased interest in low-input turfgrasses as a way to lessen the environmental and economic impacts of turfgrass management. An overlooked, but important, component of a turfgrass system is the rhizosphere. Recent advances in the area of metagenomics allow us to better understand this critical area surrounding turfgrass roots. Understanding how microorganisms associate with different species and cultivars of turfgrass may in the future provide researchers the ability to breed for turfgrass plants that form better mutualistic and beneficial relationships with soil microorganisms. Previous research in Poaceae has shown that a plants genotype has the ability to influence the rhizosphere microbial community structure. The objectives of this study were to (1) determine if turfgrass species affects soil microbial community structure and (2) identify differences in soil microbial community structure based on nitrogen fertility regime. Turfgrass species plots were maintained at a 7.6 cm mowing height for three years two nitrogen fertility levels (no fertility and 98 kg ha-1 yr-1). Rhizosphere soil samples were taken from five species of turfgrass (Koeleria macrantha, Poa pratensis, Agrostis capillaris, Festuca trachyphylla, and Deschampsia cespitosa). DNA was isolated from turfgrass rhizosphere soil and then sequenced using HiSeq Illumina using primers for both bacteria and fungi. Data was analyzed using WinSCP, Putty and Mothur. Results from this research will be able to inform turfgrass researchers about the impacts of both grass species and nitrogen fertility on soil microbial communities.